Last July, I had a local company install a new concrete driveway for me. At first I was satisfied with their work, but over the last few weeks some problems have arisen. While I was shoveling snow a while ago, I noticed that not only has the driveway already cracked all the way across, but that the surface of the cement had started to form what looked like blisters across a wide area. I noticed that if I stepped hard on the cement in that area, it make a weird crunching noise.

I kept an eye on it for a week or two, and things have really gotten worse quickly. The blisters turned into pits, and now the surface of the cement over an area of about a foot square has shattered into smaller pieces, and the blistering/pitting that I first noticed seems to be spreading. Needless to say, I'm pretty unhappy.

The company told me that the driveway was guaranteed for a year, but I don't have that in writing (I know, stupid mistake...lesson learned). I called the company owner and told him what was going on. He says that it sounds like spalling caused by the salt that people put on sidewalks and roads for de-icing. We have never used salt on the driveway, and the affected area is on a part of the driveway that the car wouldn't usually be sitting on anyway (farther from the garage than we usually park it). It seems that he's basically trying to blame the problem on me for not sealing the driveway, which I didn't know was necessary. According to my reading on the Web, properly mixed and poured cement should last for years and be able to handle road salt.

I guess my question is, is the company owner right? Is this all my fault for not applying a sealer, or can I reasonably hold them to their guarantee and ask them to redo the work?

Posting a few pictures would provide a better path to reasonably accurate advice. And without a written warranty of any kind, your chances of getting the contractor to make things right are at best, quite slim.

The crack you mentioned could be caused by inadequate control joints (number and depth), or joints that weren't installed in time while initial set was taking place. Cracks related to the latter usually show up close to one or more existing joints.

The other problem, localized failures, is often the result of soft aggregates (most common is chert) located just beneath the surface. They absorb water, increase in size especially when frozen, which causes the concrete above them to "pop out," usually leaving a single, large piece of fractured, white-colored aggregate at the bottom of the opening. If the crumbling is strictly confined to just the one area you mentioned (the defect is known as scaling), it's more likely caused by over-working that area during finishing operations, or adding too much water during finishing. And if the deterioration eventually shows up over larger areas, it could be the result of failure to specify an air entrainment admixture in the mix. Failure to utilize proper curing techniques on the fresh concrete can also result in eventual performance problems, although the most common symptoms of that would be closely-spaced, shallow map-type cracks.

Concrete flatwork placed with reasonable care stands a better chance of resisting freeze-thaw cycles if it is sealed before freezing temperatures are experienced. Your failure to do so may have contributed to the deterioration rate of your driveway, but there are other things going on that are the root cause of the problem(s). I've personally poured dozens of driveways and patios, and often didn't apply any sealers of any kind. And I'm aware of only one that developed a scaling problem, caused by over-working (with added water) an area that had developed a flash-set while finishing.

The best way for an accurate assessment of what you have is to request an analysis by a concrete testing lab. They will take some samples, and perform a spectroscopic examination of same. The usual charge of several hundred dollars (for minimal sample analysis) varies by location, but the specific results you would be given will be worth it should you need verification of what was done incorrectly, to validate your request for a new driveway from the contractor. A Small Claims Court claim might be your best means of resolution.

Here are a few pictures of the worst area. It's about one foot by two feet long. It's really affected a much larger area, though. If you press down with your fingers on the cement all around the spot, it gives as if there's air between the surface layer and the lower layer of concrete. I just have a hard time believing that even if a little salt got on the driveway and caused damage, that it could be this extensive after just a few months.

I got in touch with the contractor and, while he sounded pretty grouchy about it, he's going to come by sometime in the next few days to look at it. I'm hoping that we can reach some kind of agreement without having to resort to small claims court.

Bridgeman: just a couple questions to clarify.
Do they use the same salt on brides that might have found it's way onto this driveway?
Would you expect to see this kind of dammage caused by salt and over what period of time?

Holy crap! That is definitely not the result of salt and/or not applying a sealant.
Looks like a paper thin layer of concrete smoothed out over rough aggregate.
From what I'm seeing in the first pic, you can expect this hole to grow 10x in size.
I would settle for nothing less than having the entire driveway torn up and repoured.

That is not a salt problem or even the calcium cloride they are using now. That looks like a mix issue. If I was the contractor, I would not be happy with my supplier....unless it was July, and the ground took all my water.

I see some very big placement and finishing problems. If it a mix from a ready-mix concrete plant the volume is a load is so large and spread out, there would more of a general problem over a large area and fairly uniform. If the contractor made the mistake of mixing on site, that could account for the apparent differences in the concrete is some areas, but more can be expected to show up over time.

I also suspect the concrete used was not air-entrained to increase durability in area prone to freezing.

What the pix show is not salt damage, nor is it damage resulting from just overworking the finish with a minimal amount of "baptizing" water. That type of failure is always much shallower, and often doesn't loosen any large rock in the mix.

There appears to be a complete matrix failure of significant depth, and the causes of same can best be determined by lab analysis of core samples. It would be worthwhile to sweep off all of the loose material, then tap soundly with a hammer on what's exposed underneath to see how badly the deterioration is and how far it goes down. I suspect the concrete underneath will be soft and pulpy. Before the contractor shows up, it would also be a good idea to sound the adjacent (undamaged) areas with a chain-drag, which will show where more deterioration will soon be visible by the differences in sound. Delaminated areas will sound dull and hollow, instead of having a higher-pitched, almost ringing sound.

Could have been caused by a gasoline spill if they used a power trowel and refueled it while standing out on the slab (I've seen it done!), or even something as simple as adding a concentrated set-retardant admixture directly into the agitating mixer on-site, instead of adding it with water at faster mixing revolutions.

Hopefully, the supplier and contractor will see the problem as being their responsibility to make right.

Well, after about a month of playing phone tag and getting ignored, I got fed up and filed complaints against the company with BBB and AngiesList. I got his response to the BBB complaint today - he's sticking to the magnesium chloride excuse and will not admit any fault, and is refusing to replace or repair the concrete or refund any money.

He described the problem as "a few small areas of surface decomposition" and claimed that he had come to the house and inspected it. If he did, I sure never saw him, and I'm home most of the time.

I comforted myself a bit by posting my photos to the Angie's List review. No response from the Angie's List people yet. I am feeling pretty helpless and angry and don't really know what to do next. If I could prove through some kind of independent analysis that the concrete failed and salt wasn't the problem it might help, but I don't know how to find a company that does that kind of thing for residential properties and probably couldn't afford it anyway.